1. Field of the Invention
The present invention relates to a resin composition having lubricating properties.
2. Description of the Prior Art
Among various synthetic resins, thermoplastic resins such as polypropylene, polyethylene, polyamide, polycarbonate, polyvinyl chloride, ABS resin and EVA resin, and engineering plastics having good heat resistance and excellent mechanical strength, such as polyphenylene sulfide (PPS) and modified polyphenylene oxide (PPO), are poor in the self-lubricating properties although they have good frictional properties. They have better lubricating properties than rubber, but they are still substantially inferior to tetrafluoroethylene resins and can not be regarded as being useful as lubricating materials. In order to improve the lubricating properties of these synthetic resins, various methods have been employed wherein a fine powdery solid lubricant such as a tetrafluoroethylene resin, graphite, molybdenum disulfide or boron nitride, a synthetic oil such as silicone oil or fluorinated oil which is liquid at normal temperature, a natural oil such as a mineral oil, or a lubricating coating material comprising the above-mentioned lubricant and a binder, is incorporated in a resin or is coated on the surface of the resin. However, the method of incorporating the solid lubricant or liquid oil to the resin, has problems such that uniform dispersion of the additives is difficult, and the intrinsic properties of the synthetic resin as the substrate are likely to deteriorate. Thus, no adequate lubricating properties have been imparted. On the other hand, the method of applying such a lubricating agent on the surface of the resin to form a coating film having lubricating properties, has had drawbacks such that the formed coating film has poor abrasion resistance and is susceptible to peeling.
Thus, conventional synthetic resins having various excellent properties have a problem that they are not suitable for use as a sliding material which is required to have a low friction and excellent abrasion resistance.